“ InstantiationException：零参数构造函数” --->怎么做？

Question

I have already read things about that but can't find a way to fix my problem anyway (Beginner here...) So, I'm currently developping an Android Studio App. I have just done fragments to have different tab on a screen. Previously I have done a "bluetooth and a bluetoothService" activity who was perfectly working. However, since I have implements these fragments I got this error

 java.lang.InstantiationException: java.lang.Class<com.example.thibaud.dogbotapp.bluetoothService> has no zero argument consde here

So I have tried to do an empty constructor but I don't know how to do it properly...

This is the begin of my bluetoothService class :

public class bluetoothService  {


private static final String TAG = "bluetoothService";

private static final String appName = "DogBot";

private static final UUID MY_UUID_INSECURE =
        UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

private final BluetoothAdapter btAdapter;



Context mContext;

private AcceptThread mInsecureAcceptThread;

private ConnectThread mConnectThread;
private BluetoothDevice mmDevice;
private UUID deviceUUID;
ProgressDialog mProgressDialog;

private ConnectedThread mConnectedThread;


/*public bluetoothService(Context context) {
    mContext = context;
    btAdapter = BluetoothAdapter.getDefaultAdapter();
    start();
}*/

start() method here :

 public synchronized void start() {
    Log.d(TAG, "start");

    // Cancel any thread attempting to make a connection
    if (mConnectThread != null) {
        mConnectThread.cancel();
        mConnectThread = null;
    }
    if (mInsecureAcceptThread == null) {
        mInsecureAcceptThread = new AcceptThread();
        mInsecureAcceptThread.start();
    }
}

Well, first post here sorry if it's not perfect, hope you guys will be able to help ! Thanksar

Answer 1

A zero-argument constructor is declared like so:

public ClassName() {
//Constructor tasks go here
}

Hope it helps

EDIT:

And yes, as davidxxx stated, you should always start class names with upper case letters. eg ClassName as opposed to className . Variable names, however, start with lower case such as variableName .